X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fbitboard.cpp;h=89eeee611f8d4dd2a8671229237aab49aeb10515;hb=e18619d07802882136b583a01e56791b61abede6;hp=8146ce9722843eafc7ff9370cf161f96edeb933b;hpb=9b1274aba3cad440b925283fe7407954743ade78;p=stockfish

diff --git a/src/bitboard.cpp b/src/bitboard.cpp
index 8146ce97..89eeee61 100644
--- a/src/bitboard.cpp
+++ b/src/bitboard.cpp
@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2023 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -16,17 +16,21 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include "bitboard.h"
+
 #include <algorithm>
 #include <bitset>
+#include <initializer_list>
 
-#include "bitboard.h"
 #include "misc.h"
 
+namespace Stockfish {
+
 uint8_t PopCnt16[1 << 16];
 uint8_t SquareDistance[SQUARE_NB][SQUARE_NB];
 
-Bitboard SquareBB[SQUARE_NB];
 Bitboard LineBB[SQUARE_NB][SQUARE_NB];
+Bitboard BetweenBB[SQUARE_NB][SQUARE_NB];
 Bitboard PseudoAttacks[PIECE_TYPE_NB][SQUARE_NB];
 Bitboard PawnAttacks[COLOR_NB][SQUARE_NB];
 
@@ -42,9 +46,8 @@ namespace {
 
 }
 
-
-/// safe_destination() returns the bitboard of target square for the given step
-/// from the given square. If the step is off the board, returns empty bitboard.
+// safe_destination() returns the bitboard of target square for the given step
+// from the given square. If the step is off the board, returns empty bitboard.
 
 inline Bitboard safe_destination(Square s, int step) {
     Square to = Square(s + step);
@@ -52,8 +55,8 @@ inline Bitboard safe_destination(Square s, int step) {
 }
 
 
-/// Bitboards::pretty() returns an ASCII representation of a bitboard suitable
-/// to be printed to standard output. Useful for debugging.
+// Bitboards::pretty() returns an ASCII representation of a bitboard suitable
+// to be printed to standard output. Useful for debugging.
 
 std::string Bitboards::pretty(Bitboard b) {
 
@@ -72,17 +75,14 @@ std::string Bitboards::pretty(Bitboard b) {
 }
 
 
-/// Bitboards::init() initializes various bitboard tables. It is called at
-/// startup and relies on global objects to be already zero-initialized.
+// Bitboards::init() initializes various bitboard tables. It is called at
+// startup and relies on global objects to be already zero-initialized.
 
 void Bitboards::init() {
 
   for (unsigned i = 0; i < (1 << 16); ++i)
       PopCnt16[i] = uint8_t(std::bitset<16>(i).count());
 
-  for (Square s = SQ_A1; s <= SQ_H8; ++s)
-      SquareBB[s] = (1ULL << s);
-
   for (Square s1 = SQ_A1; s1 <= SQ_H8; ++s1)
       for (Square s2 = SQ_A1; s2 <= SQ_H8; ++s2)
           SquareDistance[s1][s2] = std::max(distance<File>(s1, s2), distance<Rank>(s1, s2));
@@ -106,12 +106,17 @@ void Bitboards::init() {
 
       for (PieceType pt : { BISHOP, ROOK })
           for (Square s2 = SQ_A1; s2 <= SQ_H8; ++s2)
+          {
               if (PseudoAttacks[pt][s1] & s2)
-                  LineBB[s1][s2] = (attacks_bb(pt, s1, 0) & attacks_bb(pt, s2, 0)) | s1 | s2;
+              {
+                  LineBB[s1][s2]    = (attacks_bb(pt, s1, 0) & attacks_bb(pt, s2, 0)) | s1 | s2;
+                  BetweenBB[s1][s2] = (attacks_bb(pt, s1, square_bb(s2)) & attacks_bb(pt, s2, square_bb(s1)));
+              }
+              BetweenBB[s1][s2] |= s2;
+          }
   }
 }
 
-
 namespace {
 
   Bitboard sliding_attack(PieceType pt, Square sq, Bitboard occupied) {
@@ -123,7 +128,7 @@ namespace {
     for (Direction d : (pt == ROOK ? RookDirections : BishopDirections))
     {
         Square s = sq;
-        while(safe_destination(s, d) && !(occupied & s))
+        while (safe_destination(s, d) && !(occupied & s))
             attacks |= (s += d);
     }
 
@@ -211,3 +216,5 @@ namespace {
     }
   }
 }
+
+} // namespace Stockfish